There is nothing wrong with a refurbished Mac. Same 30 day return/replace policy no questions asked. Same 1 year hardware warranty and applicable for Apple Care. Sometimes when you get a Refurbished mac, you get a bonus that isn't listed such as a bigger HD or more RAM depending on what model is available when you buy and what is in stock.
Advantages to previous generation models:
Cheeper
Time Tested (Previous revision kinks have been worked out)
New Sandybridge machines are a rev A. like board which may not have all the bugs worked out along with a new video card/processor.
A 17" MacBook Pro previous generation will have a much higher resolution than the current 15.
To fit the budget you're looking at, you could get a refurbished previous generation or wait until the current generation refurbished computers start showing up. Lastly, because of the connection on both the previous and current generation, you'll see a vast boost in speed with an SSD. Which can be added later.
As a final note, yes a Virtex3 is fast, but the Crucial one is comparable and more budget friendly. Also, look for refurbished macs with SSDs in them.
For instance:
http://store.apple.com/us/product/G0GPDLL/A?mco=MTg1Njg5ODA Doubles the size of the SSD (256) and gives you a 17" display.